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ap biology plant systems transpiration essay
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Investigate the Effect of Temperature on Cell Membranes and Membrane Structure
If you read a recipe for cooked beetroot it will usually recommend
that you don’t remove the outer skin of the beetroot and don’t cut off
al the stalk and root if you want to avoid getting lots of red dye in
the cooking water. Beetroot contains red pigments called betalains,
located within the cell vacuole. Normally the pigments can’t pass
through membranes but they leak out when the beetroot is cooked.
Aim – The aim of this practical is to use beetroot to examine the
effect of the temperature on cell membranes and relate the effects
observed to membrane structure. To function correctly a cell needs to
be able to control transport across the partially permeable cell
membrane.
Theory – To understand how the red pigment leaks out of the beetroot
it is essential that we understand the molecular Structure of a plasma
membrane.
A membrane is a phospholipid bilayer. This means that it has two
layers of molecules called phospholipids. Each of these phospholipid
molecules
has two parts:
• A 'head' that will mix with water but not with fat (i.e. it is
hydrophilic)
• Two 'tails' that will mix with fat but not with water (i.e. they are
hydrophobic).
In the phospholipid bilayer, the hydrophilic heads are always on the
outside of the membrane. The hydrophobic tails are always on the inside
of the membrane. Alone, this arrangement of phospholipids would form
a barrier to water and to water-soluble substances. However, other
molecules are scattered among the phospholipids. These include lipids
(including cholesterol in the membranes of animals), proteins and
polysaccharides. The proteins in membranes are of special interest to
us. This is because they have a number of important functions. Proteins
function as:
• Carriers for water-soluble molecules (such as glucose)
• Channels for ions (such as sodium and chloride ions)
• Pumps, which use energy to move water-soluble molecules and ions
• Receptors, which enable hormones and nerve transmitters to bind to
specific cells
• Recognition sites, which identify a cell as being of a particular
type
• Enzymes, which speed up chemical reactions at the edge of the
membrane
The ways that substances move across cell membrane are
1. Diffusion
2. Active transport
3. Faci...
... middle of paper ...
...ees Celsius. Because at 30 degrees
Celsius I would have presumed that the membrane would have been fairly
stable. However my graph shows the contrary. This might be due to
sources of error in my experiment.
Experiments - I have successfully gained my results that back my
hypothesis. However the results have limitations and some sources of
error. The size of the beetroot is essential. In my experiment I used
a ruler and cork bore to measure out the same size beetroot. The cork
borer was a a good aid as it ensured that the beetroot had the same
diameter. However using a ruler could present possible error. Due to
the surface area to volume ratio.
As the test tubes were taken out of the water bath and placed the in
the colorimeter the temp reduced by a few degrees. This small error
could of change the results by 0.5 percent inaccuracy. This is because
of insufficient equipment.
I understand this experiment is only on a small scale but to gain
better results each test tube going up in 10 degrees Celsius so we can
tell the point of denaturing more accurately, however I feel that I my
experiment showed breath of how a membrane functions under temperature
change.
Nikiforuk’s article is written to argue a point and persuade the audience, non-specialist individuals, to his claim. There are many methods used to achieve this. Starting in the introduction Canada is glorified for what it used to be known for, then that image is quickly juxtaposed with the now dark and destabilized country because of the developing tar sands (Nikiforuk 211). This introduction, which uses pathos by using strong words to evoke negative e...
osmosis, it can works both ways so that it can pass into and out of
The Alberta Oil Sands are large deposits of bitumen in north-eastern Alberta. Discovered in 1848, the first commercial operation was in 1967 with the Great Canadian Oil Sands plant opening, and today many companies have developments there. The Alberta Oil Sand development is very controversial, as there are severe environmental impacts and effects on the local Aboriginal peoples. This essay will discuss the need for changes that can be made for the maximum economic benefit for Canada, while reducing the impact on the environment and limiting expansion, as well as securing Alberta’s future. Changes need to be made to retain the maximum economic benefits of the Alberta Oil Sands while mitigating the environmental and geopolitical impact. This will be achieved by building pipelines that will increase the economic benefits, having stricter environmental regulation and expansion limitations, and improving the Alberta Heritage Fund or starting a new fund throu...
The Alberta tar sands have the second largest oil reserves in the entire world, only smaller than Saudi Arabia’s oil reserves. This vast supply of oil has created a large interest in the extraction and then production of different types of oil in Canada. The tar sands are believed to hold around 174.5 billion barrels of oil. The estimates are across the board but if it is true, the oil industry in Canada would become its largest export and substantially boost the economy. The tar sands were producing 53% of Canada’s oil output, but by the end of this year it will be around 83%. This number could increase to 99%, if the tar sands are fully taken advantage of. The extraction of oil has already begun and covers around 602 square kilometers of land. The problem is that ...
According to one government analysis, the crude from Canada’s oil sands will emit seventeen percent more greenhouse gas pollution than there processes used for conventional oil, making it even more controversial against environmentalists (Davenport par. 6). The concerns are reflected in great quantity of carbon in the tar sands, “Ensure that they will play an important role in whether or not climate change gets out of hand” (Clayton 2). In addition, the Environmental Protection Agency (E.P.A) noticed the impact it would have on greenhouse gas emissions. According to the E.P.A., “The recent drop in global oil prices might mean that contraction of the pipeline vault spur increased development of Canadian oil sands—and thus increase planet-warming greenhouse gas emissions” (Davenport par
The site of the Old Globe Theatre was rediscovered in the 20th century and a reconstruction started to take place as near to the place as possible. This is the theatre which still stands today, and which has been running, and holding many performances including ones written by Shakespeare.
Gordon makes a great argument about doctor and nurse relationship. She states that in fact “many doctors still consider nurses to be their handmaidens,” although they are supposed to work together as a te...
In today’s world humans are consuming massive amounts of fossil fuels. The top five oil consuming countries in the world are the usual suspects. These include the United States, China, Japan, India and Russia. Canada comes in at number 10 with a daily consumption of 2,287 thousand barrels per day. There are three major types of fossil fuels: coal, oil and natural gas. These resources were formed during the Carboniferous Period 360-286 million years ago. During this time earth was covered in swamps with large amounts of plants and waters filled with algae. When these plants and trees began to die they would form layers of peat. Hundreds and thousands of years would pass adding sand and other materials on top of the peat. This formed the sedimentary rocks we know today. As the thousands of years turned into millions of years the water of the peat layer was pushed out of the peat until the layer of diatoms turned into coal, oil or natural gas (CEC, 2013). Canada has oil industry throughout the country and currently 12 out of 13 provinces are active in the oil industry. Natural gas production is occurring in British Columbia, Alberta, Quebec, and New Brunswick. Natural gas could also become large industry in Prince Edward Island, Nova Scotia, Newfoundland & Labrador, Yukon and the Northwest Territories. Oil production is currently taking place in the provinces of Alberta, Saskatchewan, Manitoba, Ontario, New Brunswick, and Newfoundland & Labrador (CAPP, 2013).
Since the rise of the Alberta oil sands, the contribution of greenhouses gas emissions has been increasing dramatically. Alberta has only 10% of Canada’s population but emits the most greenhouse gases than any province. Also, the oil sands are the largest source of carbon dioxide emissions in Canada ("Oil Sands Truth." Para 4). Additionally, although it takes a lot of energy going into producing the bitumen from the oil sands, the energy output is relatively low. A about three times water is needed for one portion of bitumen when it is being processed after being accessed from the oil sands. Not only is water wasted, but the water supply n the area is heavily polluted. There is more than three million gallons of toxic run off from the plants every day. To contain this, majority of polluted water and tar is segregated and turned into toxic pools which are deposits of a combination of chemicals and polluted water. These pools now cover about fifty square miles in the oil sands location ("Tar Sands Oil: Pros and Cons." Para 1). To make room for the industry, the boreal forest is being cut down at a rapid pace. This not only depleted forest cover but the boreal forest counters the carbon emissions from the sands but with less forests, there will be an even greater rise in carbon emissions. The land is also being harmed due to the construction of large pipelines to access consumers far away. Not only do the oil sands harm the inorganic aspects of the environment in the location but animals are harmed due to their habitats being destroyed both on land and in the water ("Pros and Cons: Alberta Oil Sands." Para 4). The rivers and streams near the oil sands are being polluted and more fish and other aquatic animals are getting sick and dying. This in turn affects the individuals who fish for a living or acquire the fish as a main dietary source. With less fish to obtain,
Lee, P., and Timoney, K.P. (2009). Does the Alberta tar sands industry pollute? The scientific
Often time, nurses has been viewed by patients, their family members and the medical team as basic emotional care givers, pill crushers or cart pullers and not as healthcare professionals who are more interesting in health promotion, disease prevention and better patient outcomes. They also often forget the emotional, physical, mental, and caring part that is involved with the profession. And to make matters worse, nurses are continued to be viewed as a threat by doctors more than ever before especially with the opening of Nurse Practitioners programs.
5. A second test tube was then filled with water and placed in a test
When a liquid phase and dry granular material are added to each other, then different forms of liquid distribution can be noted:
People are always going to go shopping. A lot of our effort is just: 'How do we make the retail experience a great one? '” - Philip Green
Here, visual merchandising will be a beneficial tool in defining the exclusive identity of the brand and thereby increasing the sales and their market value. It is the appropriate time that the Indian retail industry understands and adopts the beneficial traits visual merchandising rather than the traditional practices of display of products and communication via sales personnel. The customers are trends aware and the stores on the other hand have managed to up the glamour quotient. Only a link of brand communication between the brand products and shoppers remains missing. (Pundir, 2007)